Automatic train control



Jan. 2, 1934. D. H. SCHWEYER AUTOMATI C TRAIN CONTROL Filed July 27.1929 2 Shee ts-Sheet l inhuman! Jan. 2, 1934. D. H. SCHWEYER AUTOMATICTRAIN CONTROL Filed July 27, 1929 2 Sheets-Sheet 2 I i 8 I NQ I==Patented Jan. 2, 1934 UNITED STATES PATENT OFFICE 21 Claims.

The present invention relates to automatic train control, and aims toprovide a novel apparatus for and method of transmitting signal impulses from the trackside to a moving train or vehicle.

The invention has for an object the provision of novel means forselectively energizing the track rails or other trackside elements withdifferent frequencies of alternating or fluctuating electrical currentor currents having different characteristics, for purpose of traincontrol, de pending on traflic conditions.

Another object is the provision of novel vehicle means for receiving theimpulses from the track rails or other trackside elements andcontrolling a plurality of relays or other devices for controlling thetrain, operating signals, or performing other functions, in accordancewith trafiic conditions and the control of the trackside equipment.

With the foregoing and other objects in View, which will be apparentwhen the invention is more fully understood, the invention resides inthe apparatus and method hereinafter described and and claimed, it beingunderstood that changes can be made within the scope of what ishereinafter claimed within the spirit of the invention.

The invention is illustrated in the accompanying drawings, wherein-Figure 1 is a diagrammatical View of one embodiment of the invention asapplied on the vehicle.

Fig. 2 is a diagrammatical view of a portion of the vehicle equipmentillustrating the use of electron tubes or valves.

Fig. 3 is a diagrammatical view of a portion of the track with aselective control for the track circuit.

Fig. 4 is a diagrammatical View illustrating trackside equipmentincluding home and distant control relays.

Fig. 5 is a diagrammatical view illustrating the use of a polarizedrelay in the trackside equipment.

Fig. 6 is a diagrammatical view of another embodiment of tracksideequipment.

Fig. '7 is a diagrammatical View illustrating still another embodimentof the trackside equipment.

Fig. 8 is a diagrammatical view illustrating a modification in thetransformers shown in Fig. 7.

Referring to Fig. 3, the track circuit feed wires 13, 14, 15 and 16 areconnected with sources of current, each having differentcharacteristics,

as hereinafter referred to, and are connected, respectively, to switches17 cooperable with contacts 18, switches 19 cooperable with contacts 20,switches 21 cooperable with contacts 22, and

switches 23 cooperable with contacts 24. The

contacts 18, 20, 22 and 24 are connected by wires 25 with the trackrails or trackside elements 26, so that when any pair of switches ismoved against the corresponding contacts, the rails or elements 26 willbe energized with the corre- 5 spending current.

The switches 17, 19, 21 and 23 are controlled by the respectiveelectromagnets A, B, C and D, the circuits of which may be controlled bysuitable wayside circuits (not shown) which form 7 no part of thepresent invention. In fact, the switches may be controlled by othermeans, either electrical, mechanical, pneumatic, manual, or the like, sothat the switches 1'? are closed for clear conditions, the switches 19are closed and the switches 1'? opened for a reduced speed, the switches21 are closed and the switches 17 and 19 opened for a still lower speedrestriction, and the switches 23 are closed and the other switchesopened for a still further restriction in train speed.

The train or vehicle equipment includes a receiver 2'7 movable over therails or elements 26 and including a core 28 extending transverselyacross said rails and having coils 29 thereon to receive pulsatingcurrent by induction from the rails 26.

The coils 29 are connected in additive relation in a circuit 30 which isconnected by a transformer 31 with any suitable rectifier 32, the outputterminals of which are connected to the primary of a transformer 33, abattery or other source of direct current 34 being preferably connectedin the primary circuit.

Contacts 35, 36, 3'7, 38 and 39 engage the secondary of the transformer33, and electromagnets a, b, c and d are connected across said contactsin succession, a rectifier 40 and condenser 41 being connected in thecircuit of each electromagnet. Rectifiers 40 are asymmetric units per-100 mitting current to flow therethrough in one direction only. Thecondensers are used for tuning the circuits so that the respectiveelectromagnets are energized by pulsating direct currents of thecharacteristic controlled by the cor- 105 responding relays A, B, C andD of the trackside equipment.

The relays a, b, c and 11 control the respective switches 42, 43, 44 and45 or other suitable devices for controlling the brakes and speed con-110 trol of a train, signals, or the like. The switches 4.2, 43, it and45 may represent signal devices or may be taken to represent thecontrolling elements of suitable automatic mechanism for enforcing speedrestrictions.

In operation, assuming the traffic conditions to be clear, the relay Ais energized to close the switches 17, and the relays B, C and D aredeenergized so that the switches 19, 21 and 23 are open, as seen in Fig.3, current having the characteristic of circuit 13 is impressed from thewires 25 into the track rails or trackside elements 26,

which current will be picked up by the receiver 2'7 and transmittedthrough the transformerfil, rectifier 32 and transformer 33.

This will affect the relay a so that it picks up or closes the switch42, thereby providing clear conditions on the vehicle, and the switchesor elements 43, i4; and 15 remaining down.

Under different speed restrictions, one of the relays B, C, D isenergized with the remaining trackside relays deenergized, so as toconnect the corresponding circuit l4, 15 or 16 with the track rails 26,thereby impressing current of corre- -sponding characteristic thereon,and same being picked up by the receiver 27 will result in thecorresponding relay 1;, c or (i being energized to lift thecorresponding switch or element.

Under danger conditions, all of the trackside relays are deenergized,thereby deenergizing the rails 26, so that the vehicle equipment doesnot receive energy from the rails, and all of'the vehicle electromagnetsor relays a, b, c and d will be deenergized, thereby establishing dangerconditions on the vehicle.

tor driven mechanism and other moving parts requiring periodicattention.

The use of a tuning condenser in series with the secondary of atransformer and a control relay, as used for the relays a. b, c and d,is disclosed in my Patent No. 1,342,873, granted June 8, 1920, and theuse of pulsating direct current between the trackside and vehicleequipments is disclosed in my application Serial No, 301,021, filed Aug.21, 1928.

Fig. 2 illustrates the'use of a pair of electron nected to the grid 53of one valve and to the filamerit of the other valve, and the other wire30a is' connected to the filament of the first named valve and to thegrid of the second named valve. The valves thus serve as a double waverectifier,

' each valve pe *mitting one-half of a wave to pass "wires 13c and withthe wires 250 leading to the rails or trackside elements. Relays H andD, respectively, re provided. When the H relay is energized it raisesthe switches against contacts to connect the wires 13c and 250. When theD relay is energized the switches are raised against contacts 200, andswitches l'ls of the H relay are dropped when this relay is deenergizedagainst contacts 1333, thereby connecting the wires lac with the wires250 through the switches 19c, contacts 200, contacts 18:0, and switches17:10, the switches 170 being removed from the contacts 180.

Fig. 5 illustrates the use of a trackside polarized relay, liaving theneutral switches 17d and the polarized switches 19d. When current flowsin one direction through the relay, the switches 19d engage contacts towhich the wires 13d are con nected, to connect said wires through saidcontacts and switches with the switches 17d engaging contacts to whichthe wires 25d are connect- When the current flows in the oppositedirection through the relay, the switches 19d move against contacts towhich the wires are connected, thereby connecting said wires led withthe wires 25d. The switches 17d drop open whenthe is deenergizcd todisconnect the wires 25d from either of the wires 13d or 14d.

Fig. 6 illustrates a trackside equipment wher in the line wires issimultaneously carry differentcycles or frequencies of fluctuatingcurrent which are selectively transmitted by a transformer 26 totransformersie, 6e and 8c, the primaries of which are connected in tunedcircuits with the secondary of the transformer 26, so that thesecondaries of the transformers 4e, 6e and Se are energized individuallyby the separate cycles or frequencies of fluctuating current. Forexample, if currents of 6, 3 and 1 cycles are impressed on the linewires 16, the transformer 4e may be tuned to 6 cycle current, thetransformer 66 for 3 cycle current, and the transformer 8e for 1 cyclecurrent.

The secondaries of the transformers ie, 66 and Se are connected throughswitches 17c, 19c and 21a with the wires 25s that are connected to therails or trackside elements 26s. The switches are controlled by therespective electromagnets A, B and C, or by other suitable means, sothat when'the switch 172 is closed, such as for clear conditions, 6cycle current is transmitted to the rails 26c, whereas if the switch isclose then 3 cycle current is transmitted to'the rails, and when theswitch 216 is closed then 1 cycle current is transmitted to said rails.

The equipment shown in 6 serves to segregate the currents of differentcycles or frequencies and to selectively transmit the segregatedcurrents to the rails or trackside elements. The arrangement shown inFig. 7 uses a single current of a specified cycle or frequency and develops currents of dierent characteristics for selectively energizingthe rails or trackside elements.

Fig. '7 illustrates still another variation in the trackside equipment,in which a source of fluctuating current of a predetermined cycle or frequency is stepped up to provide currents of higher cycles orfrequencies.

The line wires 1 are supplied with alternating or fluctuating current oflow cycle, which is transmitted through a transformer 2 having twosecondary windings, to the circuits 3 and 60 each including one of thesecondary windings.

The circuit 3 f includes primary windings of a pair of transformers 47,said primary windings being connected in series, and the secondarywindings of said pair of transformers are connected in series in thecircuit 5] which includes in series the primary windings of a secondpair of transformers 6 The secondary windings of the transformers 6 areconnected in series in a circuit '77 which has connected in seriestherein the primary windings of a pair of transformers Si, and thesecondary windings of the last named transformers are in turn connectedin series in a circuit 9f including in series, the primary windings of afourth pair of transformers 10f.

Each transformer, as shown, comprises a closed circuit core on which thewindings are disposed, the primary windings being shown at the top andthe secondary windings at the bottom of the cores.

Each of the circuits 3 5), 7i and 9] includes an adjustable condenser 12for tuning the circuit, such condensers being used to correct the powerfactor.

The lead off wires 13f, 14 and 15 are connected to the circuits 5 7i and9 respectively, between the pairs of secondary and primary windings ofthe successive transformers, so that currents of different cycles may betaken from the several circuits and transmitted to the rails ortrackside elements 261, the switches 1'7), 19f and 21 and their contacts18), 201 and 22 connecting the wires 13 14 and 15 selectively with thewires 25 under the control of the electromagnets A, B and C.

The circuit 60 includes full-wave rectifying means 61 so as to providefor unidirectional current in said circuit, and windings 62 are providedon the transformers and are connected in multiple or parallel to thecircuit 60, so as to impress unidirectional magnetic flux in the coresof the transformers. It will be noted that the windings of each pair oftransformers are connected in series.

The windings are all in the same direction with respect to the flow ofmagnetic flux in the cores, excepting that one secondary winding of eachpair is wound reversely. As a result, the series of transformers andtheir circuits produce a cascade action in increasing the cycle orfrequency of current in the successive circuits 5 7 and 9 under theprinciple of known frequency doublers.

The alternating magnetic flux induced into the cores of each pair oftransformers, together with the action of the magnetic flux produced inthe cores by the windings 62, will induce through the opposed secondarywindings a fluctuating current of double the cycle or frequency. Secondharmonics are produced that double the cycle or frequency of the currentin passing from each circuit to the next, and consequently the circuits5 '7 and 9 are energized by fluctuating currents of increased or doubledcycles in succession.

For example, if the line wires 1f receive 4 cycle current, then thecircuit 5) is energized by current of 1 cycle, the circuit 71 by 3 cyclecurrent and the circuit 9] by 6 cycle current.

The currents of different cycles or frequencies may thus be selectivelytransmitted to the track rails or trackside elements 261 in the samemanner as described in connection with Fig. 3, through the relays A, Band C. The circuits 13f, 14f, and 15;, correspond with circuits 13, 14and 15, Fig. 3, respectively.

Fig. 8 illustrates a modification in the transformers used in thehook-up shown in Fig. 7,

in that the core has a cross yoke between the primary and secondarywindings on which the winding 62a of the unidirectional or directcurrent is disposed, the effect being the same.

Having thus described the invention, what is claimed as new is:

1. The method of energizing trackside train control elements consistingin continuously generating from a single source, at least three currentsof different frequencies obtained one from the other, and selectivelytransmitting a single one of such currents to said elements anddisconnecting the other currents from said elements.

2. The method of energizing trackside train control elements consistingin continuously generating, from a single source, a series of more thantwo currents of progressive frequencies obtained one from the other, andselectively transmitting but one of such currents to said elements.

3. The method of energizing trackside train control elements consistingin continuously generating, from a single source, a series of more thantwo currents obtained one from the other which from each current to thenext is doubled in frequency, and selectively transmitting a single oneof such currents at a time to said elements.

4. The method of energizing trackside train control elements consistingin continuously generating, from a single source, by induction andinductive control a series-of more than two currents of progressivefrequencies obtained one from the other, and selectively transmitting asingle one of such currents at a time to said elements.

5. Train control apparatus comprising trackside elements, means forcontinuously generating, from a single source, at least three currentsof different frequencies obtained one from the other, and means forselectively transmitting such currents one at a time to said elements.

6. Train control apparatus comprising trackside elements, means forcontinuously generating, from a single source, a series of more than twocurrents of progressive frequencies obtained one from the other, andmeans for selectively transmitting such currents one at a time to saidelements.

'7. Train control apparatus comprising trackside elements, means forcontinuously generating, from a single source, a series of currentsobtained one from the other each of which is double the frequency ofanother one, and selectively transmitting such currents to said elementsalways in the same relative polarity.

8. Train control apparatus comprising trackside elements, means forcontinuously generating, from a single source, by induction andinductive control a series of currents of progressive frequenciesobtained one from the other, and means for selectively transmitting saidcurrents to said elements always in the same relative polarity.

9. Train control apparatus comprising trackside elements, a singlesource of fluctuating current, a series of more than two circuitsinductively connected with said source and having means for controllingthe frequency of currents therein so that such circuits are energized bycurrents of different frequencies, means for selectively connecting saidcircuits with said elements and vehicle carried elements each responsiveto one of said frequencies alone.

10. Train control apparatus comprising trackside elements, a singlesource of fluctuating current, a plurality of circuits inductivelyconnected with one another and with said source, a rectifier controllingthe frequencies of currents in said circuits so that said circuits areenergized by currents of progressive frequencies, and means forselectively connecting said circuits one at a time with said elements.

11. Train control apparatus comprising trackside elements, a singlesource of fluctuating current, a plurality of circuits, transformersinductively connecting said circuits in cascade with said source, arectifier in the circuit of one of said transformers controlling thefrequencies of currents in said circuits so that said circuits areenergized by currents of different frequencies, and means forselectively connecting said circuits with said elements.

12. The method of transmitting control influences from the trackside toa moving vehicle consisting in continuously generating, from a singlesource, at least three currents of different frequencies obtained onefrom the other, selectively transmitting said currents one at a time totrackside elements, picking up on a vehicle the current from saidelements, and selectively controlling a plurality of vehicle devicesfrom the individual picked up currents.

13. Train control apparatus comprising trackside elements, means forcontinuously generating, from a single source, at least three currentsof different frequencies obtained one from the other, means forselectively transmitting said currents one at a time to said elements,pick-up means on a vehicle cooperable with said elements for receivingthe different currents therefrom, a plurality of vehicle devices, andmeans selectively controlling said devices from said pick-up meansaccording to individual currents of different frequencies.

14. Train control apparatus for a single block comprising tracksideelements, a source of fluctuating current, a series of more than twocircuits, transformers inductively connecting said circuits in serieswith said source, a rectifier in the circuit of one of saidtransformers, and means for selectively connecting said circuits withsaid elements.

15. Train control apparatus for a single block comprising tracksideelements, a source of fluctuating current, a series of more than twocircuits, transformers inductively connecting said circuits in serieswith said source, means influencing said transformers for doubling thefrequencies of the currents in said circuits in succession, and meansfor selectively connecting said circuits one at a time with saidelements.

16. In a system for energizing a track circuit, the combination, a pairof transformers, a primary coil on each transformer, a circuitconnecting said primary coils in series With a source of energy, asecondary coil on each of said transformers, a secondary circuitconnecting said coils with the track circuit in series with a condenser,a third coil on each of said transformers and a circuit connecting saidthird coil to an A. 0. supply through a rectifier.

17. In a system for energizing a track circuit. the combination, atransformer having a primary coil and a secondary coil, a circuitconnecting said primary coil with a source of energy, a circuitconnecting said secondary coil with a condenser and with the trackcircuit, a third coil on said transformer and a circuit connecting saidthird coil to an A. C. supply through a rectifier.

18. In a system for energizing a track circuit, the combination, atransformer having an input circuit with a primary coil and an outputcircuit with a secondary coil, a circuit connecting said primary coilwith a source of energy, a circuit connecting said secondary coil withthe track circuit and a third coil inductively coupled on saidtransformer with the other coils and connected in a circuit energizedfrom an A. C. supply through a rectifier.

19. In a system for energizing a track circuit, the combination, a pairof transformers, each having a primary coil and a secondary coil, acircuit connecting said primary coils with a source of energy, asecondary circuit connecting said secondary coils with the track circuitand another coil on each of said transformers inductively coupled withthe primary and secondary coils and connected in a circuit energizedfrom an A. C. supply through a rectifier.

20. In a system for energizing a track circuit, the combination, asingle source of current, a pair of secondary coils energized from saidsource, a plurality of transformer yokes, each having a primary and asecondary coil, the primary of the first yoke being energized from oneof said secondary coils and the primary of the second yoke beingenergized from the secondary of the first yoke and the primary of thethird yoke being energized from the secondary of the second yoke, athird coil on each of said yokes, a rectifier in the circuit of theother secondary coil and said circuit energizing said third coils andconnections for energizing the track circuit connected to the secondarycoil of each yoke.

21. In a system for energizing a track circuit, the combination, asingle source of current, a pair of coils energized from said source,two

groups of transformer yokes each connected in cascade, with thesecondary of one energizing the primary of the next and the primary ofthe first transformers of each group energized by one of said coils, athird coil on each of said transformers, a circuit for energizing saidthird coils including a rectifier and energized by the other of saidpair of coils and connections for energizing the track circuit connectedto the secondary coil of each transformer.

DANIEL HERBERT SCHWEYER.

